Multi-styli assembly for a recorder



z- 31, 1965 D. SHALER E 3,204,249

MULTI-STYLII ASSEMBLY FOR A RECORDER Filed Dec. 6, 1962 FIG.|

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FIG. 3

IN VENTORS United States Patent 3,204 249 MULTI-STYLI ASSEMBL Y FOR A RECORDER David Shaler, Waldwick, 'N.J., and Joseph R. Columbo,

Brooklyn, N.Y., assignors to Hogan Faximile "Corporation, New York, NY.

Filed Dec. 6, 1962, Ser. No. 242,828 6 Claims. (Cl. 346-139) The present invention relates to the art of recording electrically transmitted information on paper or the like, and more particularly to a multi-styli assembly for a recorder.

Multi-styli recorders are used for plotters for telemetering data reduction, to produce a spectrum analyzer display, and for the rapid converison of digital data to a finished curve or plot. In the recorders it is often necessary to provide alpha-numeric information on the plot. Electronic systems are used in which a letter is made up from information bits recorded by the multistyli assembly.

A recorder employing 1024 styli spaced at one hundred per inch is described by George M. Stamps and Hugh C. Ressler in a technical paper titled A Very High Speed Recorder presented at the Fourth National Aero- Com Symposium, Utica, N. Y., October 20, 1958, sponsored by the IRE Professional Group on Communications Systems. In the described device a recording medium is passed between a multi-styli array and a linear electrode. Electrolytic paper is used as the recording medium and thus low voltages may be used for marking.

The stylii are of the order of .008 inch in diameter and have a center to center spacing of .010 inch. Marking speeds are obtainable of the order of from one third of (an inch of copy to about 100 inches of copy per secon hundred per inch spacing, copy of eight by ten inches can be marked at rates varying from one third of a page per second up to twenty or more pages per second.

This very high speed of recording is only practically possible by the use of electronic equipment. It is quite evident that with a styli spacing of one hundred to an inch it is necessary that an alpha-numeric matrix contain more elements than in the case of fifty styli to the inch in order to provide a recorded character of the same height. The electronic circuitry to record the additional elements is expensive and unnecessary when the higher resolution obtained thereby is not required. The larger spacing is advantageous in that it enables the use of heavier and stronger styli contributing to a more rugged mechanism. The operation life of the styli assembly using heavier styli may be many times that using lighter styli.

Certain difliculties arise in the use of the heavier styli in that the styli must extend farther from their mounting block in order to maintain equal spring force as compared with lighter styli. The greater length of the styli together with the use of heavier wire presents more opportunity for the wire, if not maintained perfectly straight during assembly operations, to deviate from a desired even spaced position in a plane. The result is that adjacent stylii may vary somewhat in spacing and in their pressure against the recording medium. This difficulty is not inherent in the use of the closely placed styli both because of the use of lighter wire which is more flexible and shorter and because the styli are almost in side by side contact which tends to prevent lateral shift.

The present invention aims to overcome the difficulties presented by the use of heavier styli in spaced multistylii relationship by providing means maintaining the desired even spaced position in a plane.

In accordance with the invention this is accomplished If about 8 styli are arrayed side by side at one i "ice by the use of yielding means resisting lateral movement of adjacent styli in a multi-styli array yet permitting a restricted movement normal to the plane of the array.

Other objects and advantages of the invention will be apparent from the following description and from the accompanying drawing which shows, by way of example, an embodiment of the invention.

In the drawing:

FIGURE 1 is a perspective view of a multi-styli assembly in accordance with the invention, the mid-portion being shown as broken away.

FIGURE 2 is an end view of a portion of a multistyli assembly, illustrating characteristic positions assumed by the marking ends of the styli without use of the inventive feaure disclosed herein.

FIGURE 3 is a view corresponding to FIGURE 2 illustrating the improved positioning of the marking ends of the stylii realized by practicing the teaching hereof.

Referring to the drawing there is shown a multi-styli assembly 1 incorporating alignment means in accord ance with the invention. A mounting member block 2 is formed of an insulating material such as epoxy which may be cast about styli 3 while they are held in position by suitable supporting means. The mounting block 2 alternatively may be made of insulating blocks having matching grooved surfaces to receive the styli 3, adhesive or other means being used to hold the assembly together. In still another construction the insulating block 2 may be made in one piece and drilled to receive the styli 3.

The mounting block 2 is of generally rectangular cross-sectional shape, the sides being less than one inch in length preferably of the order of one-half inch in the dimension parallel to the plane of the styli and about five-eighths of an inch in the dimension normal to the plane of the styli, the styli being positioned in a plane located about one-eighth of an inch from one of the shorter sides.

The styli 3 are formed from full spring tempered stainless steel and may be of any desired size usually between .008 inch and .014 inch in diameter and preferably .012. The center to center spacing depends upon the number of styli per inch. For example, 20 styli per inch would require .05 inch spacing while styli per inch would require .01 inch spacing. A preferred arrangement is 50 styli per inch with the resulting .02 inch center to center spacing. The styli are suitably insulated [from each other as by an enamel coating, a contact area 4 being free of insulation. The free ends 5 of the styli 3 extend from the mounting member 2 about three-quarters of an inch. Connection ends 6 of the styli 3 may be of any desired length and may terminate in any desired manner or in a connection block as described in the Stamps-Ressler paper referred to above.

In the manufacture of the multi-styli assembly apparently some of the styli 3 become bent or acquire stresses which result in an uneven positioning of the free or marking ends 5. All wire drawn through a die tends to have a helical curvature which is straightened by further drawing not always with complete success. In FIGURE 2 there is an end View of a styli assembly in which there is a showing of characteristic positions assumed by the ends of the styli 3 before the yielding means is applied as taught herein. For example, there may be a series of styli as indicated at 8 in which the styli are in perfect position being in the same plane and equally spaced. The pairs of styli at 9 and 10 are shown in the proper plane but are spaced too closely together. At 11 and 12 the styli are spaced properly but out of the proper plane. In use one of the styli indicated at 11 and 12 may have excessive pressure against the recording medium while the other may have insufficient pressure resulting in markings of uneven optical density. At 13 and 14 the styli are shown as being improperly positioned both as to plane and linear spacing therealong. Apparently the apex of the angle of bend of the styli is approximately at the point of contact of the styli with the mounting block 2.

In accordance with the invention yielding means 15 is provided to maintain the styli in proper alignment yet permit movement thereof away from the plane of the recording medium so as to conform to possible unevenness of the surface thereof.

The resilient means '15 is most conveniently made from a material applied in liquid form and which becomes self-curing after application to form a yieldable member. Any desired material providing the proper resiliency may be used such as rubber, plastic material, or other materials forming a resilient structure. Care should be taken that the material selected is resistant to degenerate elfects from the chemicals used in the recording medium. A suitable material is manufacutred by the Minnesota Mining and Manufacturing Company of St. Paul, Minnesota, under the code number of EC 1300. This material is a liquid of high viscosity and may be applied by the use of a small stick or the like. The material cures in a few hours to provide the web or bond 15 of yieldable nature. The web 15 is preferably positioned between one-sixteenth to one-quarter of an inch and preferably about one-eighth of an inch from the block 2. The web is between one-eighth and one-quarter inch, preferably about one-eighth of an inch in width, and may vary form .010 to .030 preferably about .015 inch in thickness.

It has been found unnecessary to extend the Web 15 into contact with the block 2, and if extended further towards the outer ends of marking ends 5, there is undue interference with freedom of movement thereof. In applying the web 15, the free ends of the styli are secured by suitable means as by being positioned between a pair of surfaces at least one of which is grooved so as to provide the desired spacing. In an alternate construction the web or bond 15 may be preformed with openings of the desired size and position and slipped into position over the marking ends 6 and secured by adhesives or other known means. Still further the bond member 15 may be molded in position.

The resilient member 15 is in compression between such of the styli as tend to move too close together, but it is in tension when one or more of the styli are moved away from the desired plane as when contacted by irregularities in the surface of the recording medium. Accordingly, the resilient member will maintain even spacing of the styli in a plane thus equalizing the pressure thereof against the recording medium, yet permitting restricted movement normal to the plane of the recording medium.

While the invention has been described and illustrated with reference to a specific embodiment thereof it will be understood that other embodiments may be resorted to without departing from the invention. Therefore, the formof the invention set out above should be considered as illustrative and not as limiting the scope of the following claims.

We claim:

1. A multi-styli assembly comprising a mounting member, a plurality of styli extending from the mounting member and forming a styli array, and yieldable means carried by the styli spaced from the mounting block and maintaining the styli in alignment yet all-owing movement of individual styli in a direction normal to the plane of the styli array.

2. A multi-styli assembly comprising a mounting member, a plurality of styli extending from the mounting member and forming a styli array, and yieldable means maintaining the styli in alignment yet allowing movement of individual styli in a direction normal to the plane of the styli array, the yieldable means carried by the styli spaced from the mounting block and applied as a semi liquid and thereafter self cured to a yieldable solid so as in effect to be formed in position.

*3. A multi-styli assembly comprising a mounting member, a plurality of styli extending from the mounting member and forming a styli array, and yieldable means maintaining the styli in alignment yet allowing movement of individual styli in a direction normal to the plane of the styli array, the yieldable means carried by the styli spaced from the mounting block and having a width of approximately one-eighth of an inch.

4. A multi-styli assembly comprising a mounting membar, a plurality of styli extending from the mounting member and forming a styli array, and yieldable means maintaining the styli in alignment yet allowing movement of individual styli in a direction normal to the plane of the styli array, the yieldable means carried by the styli spaced from the mounting member approximately one-eighth of an inch.

5. A multi-styli assembly comprising a mounting member, a plurality of styli extending from the mounting member and forming a styli array, and yieldable means maintaining the styli in alignment yet allowing movement of individual styli in a direction normal to the plane of the styli array, the yieldable means applied as a semi liquid and thereafter self cured to a yieldable solid so as in effect to be formed in position, the yieldable means having a width of approximately one-eighth of an inch and carried by the styli spaced from the mounting member approximately one-eighth of an inch. I

6. A multi-styl-i assembly comprising a mounting mem ber, of generally rectangular cross-sectional shape, the sides thereof being less than one inch in width, a plurality of styli extending from the mounting member and forming a styli array, the styli being approximately .012 inch in diameter, the styli extending from the mounting block about three-quarters of an inch and positioned in a plane, the center to center spacing of the styli being about .02 inch, and yieldable bonding means maintaining the styli in alignment yet allowing movement of individual styli in a direction normal to the plane of the styli array, the yieldable means having a width of approximately one-eighth of an inch, the yieldable means carried by the styli spaced from the mounting member approximately one-eighth of an inch.

References Cited by the Examiner UNITED STATES PATENTS 2,719,775 10/55 Erving 346-139 2,779,654 l/57 Williamson 34633 2,867,491 1/59 Nelson 346141 X 2,966,726 1/61 Gallentine et al. 29-1555 2,966,727 'l/61 Gallentine et al. 29-1555 2,967,083 *1/61 Gallentine 346139 2,977,415 3/61 Breeman 178-30 OTHER REFERENCES A Very High Speed Facsimile Recorder, Stamps and Ressler IRE Transactions on Communications Systems, vol. CS-7, No. 4, December 1959, pages 257-263.

LEO SMILOW, Primary Examiner. 

1. A MULTI-STYLI ASSEMBLY COMPRISING A MOUNTING MEMBER, A PLURALITY OF STYLI EXTENDING FROM THE MOUNTING MEMBER AND FORMING A STYLI ARRAY, AND YIELDABLE MEANS CARRIED BY THE STYLI SPACED FROM THE MOUNTING BLOCK AND MAINTAINING THE STYLI IN ALIGNMENT YET ALLOWING MOVEMENT OF INDIVIDUAL STYLI IN A DIRECTION NORMAL TO THE PLANE OF THE STYLI ARRAY. 